Machine for use in the manufacture of paper filters



April 21, 1959 Filed July 19, 1954 E. PETTITT ETAL 2,882,801

MACHINE FOR USE IN THE MANUFACTURE OF PAPER FILTERS 2 Sheets-Sheet 1 IApril 21, 1959 E. PETTlTT ET AL 2,882,801

MACHINE FOR usE IN THE MANUFACTURE OF PAPER FILTERS Filed July 19, 19542 Sheets-Sheet 2 United States Patent MACHINE FOR USE IN THE MANUFACTUREOF PAPER FILTERS Leslie Ernest Pettitt, Blue Bell Hill, Rochester, andPhilip Rainham Peasey, Rochester, England, assignors to C.A.V. Limited,London, England Application July 19, 1954, Serial No. 444,283

1 Claim. (Cl. 93-1) This invention relates to the manufacture of afilter of a kind comprising two permeable paper strips, these beingunited by an adhesive along opposite longitudinal edges and spirallycoiled so that the convolutions form alternate inflow and outflowpassages separated by permeable partitions, the inflow passages beingopen to one side of the coil, and the outflow passages being open to theopposite side of the coil. Prior to combining and coiling the twostrips, one of them (hereinafter referred to as the glued strip) hasapplied to one of its sides and adjacent to one edge a narrowlongitudinal layer of adhesive, a similar layer being also applied tothe opposite side and adjacent to the other edge. During a preliminaryoperation in which the adhesive is allowed to dry partially, a longlength of this strip sufficient to make a considerable number of filtersis coiled on a reel which serves to feed a machine in which the requiredfilters are formed.

The present invention relates to the filter forming machine, and has forits object to enable the operations involved in the formation of thefilters to be effected expeditiously.

A machine in accordance with the invention comprises the combination ofa pair of guide rollers for the glued strip, these being mounted at aconvenient distance apart in approximately the same horizontal plane, apair of suspended and vertically movable guide rollers carried by theends of a flexible member passing around a supporting roller situated ata position above the first mentioned guide rollers, so as to accommodatea length of strip suflicient to make at least one filter, a spindle forcoiling the glued strip, a plain strip, and convolutionspacing tapes,and means for severing the paper strips.

In the accompanying drawings:

Figure 1 is a side elevation and Figure 2 a plan of a filter formingmachine in accordance with the invention.

Figure 3 is a diagrammatic sectional view illustrating the mode offorming a filter by the machine shown in Figures 1 and 2, and Figure 4is a diagrammatic cross sectional view illustrating a portion of thecompleted filter.

Figure 5 is a fragmentary sectional end view taken on the line 55 of,and drawn to a larger scale than, Figure 1.

Referring to the drawings, there is provided a vertical enclosure athrough which the glued strip b is caused to pass to the filter formingmechanism from a feed coil prepared as described in our aforesaidco-pending application, the glued strip having two narrow longitudinallayers of adhesive (indicated by b in Figures 3 and 4) appliedrespectively to marginal portions at opposite sides and adjacent toopposite edges of the strip. At the entrance and exit sides of thisenclosure and at about its centre are mounted a pair of guide rollers d,e, these being situated in the same or approximately the same horizontalplane. At the upper end of the enclosure is mounted a roller 1 forsupporting a pair of flexible cords g, chains or the like which at theirends are attached to a pair of rollers h which can rise and fall withinthe enclosure, one of these rollers being weighted. At the commencementof a filter-forming operation, one of the rollers h is situated at theupper end of the enclosure, and the other at the lower end. During thefilter forming operation the strip b is drawn to the coiling means at afaster rate than that at which it is fed from the feed drum, andconsequently the two vertically movable rollers h are thereby caused tomove towards each other until they reach the central position. Thelength of the strip in the enclosure is suflicient to form at least onefilter.

On leaving the enclosure the glued strip b first passes under astrip-feed roller i, and thence past a knife 1 and a guide roller k to acoiling spindle m. Also on the machine is mounted a support p for a coilof plain permeable paper strip p, a feed roller 0 and a guide roller n,a second knife j being situated between the rollers o, n. The stripsupplied from the coil is similar to the glued strip, but has noadhesive on it, and is required to be intercoiled with the glued stripso that the adhesive layers b serve, during the intercoiling operation,to attach the marginal portions of each convolution of the glued stripto opposite marginal portions of alternate convolutions of the plainstrip. Further, there are mounted on the machine supports q for a pairof coils of spacing tapes q made from any convenient material. The tapesare fed to the coiling spindle at positions adjacent to the longitudinaledges of the glued and plain strips as shown in Figure 3, and serve toexert a localised pressure on the strips b, p at positions correspondingto the adhesive for squeezing the latter between the adjacent parts ofthe strips, and thereby ensuring that the marginal portions of thestrips are effectively united as above described by the adhesive. Thefeed rollers and coiling spindle are driven by an electric motor r atsuitably co-ordinated rates.

The arrangement is such that the two paper strips b, p and the spacingtapes q are simultaneously coiled on the spindle until the requiredlength of glued strip has been fed into the machine. On completion ofthe coil, that is to say, when the spindle carries suflicient lengths ofthe two strips to form a filter, the strips are severed by the knives j,j and the action of the motor is temporarily interrupted by a clutch(not shown). While the machine is at rest, the movable rollers h in theenclosure return to their initial positions in readiness for forming thenext filter. After removal of the coil from the spindle, the tapes areshaken out and re-coiled for further use. In its finished condition thefilter consists of a coil of alternate glued and plain strips unitedtogether at opposite edges as represented by the fragmentary view inFigure 4.

In the machine forming the subject of our concurrent application forpatent above mentioned, two feed strips are formed successively in amanner which obviates intermission of feed to the filter making machine,the feed coils occupying adjacent positions. After the whole of one feedcoil has been utilised on the filter making machine, the coilingmechanism of this machine is moved laterally to bring it into line withthe next available feed coil, the said mechanism being mounted on aslide s which is movable on a fixed guide t on the bed of the machine.

The knives j, j are similar to each other, and may have any convenientform. Thus, each of these knives may have the form of a pivoted andspring-loaded blade as exemplified in Figure 5 in which the knife 1' isshown pivoted on a horizontal axis at u and loaded by a spring w, thisknife being movable by hand about its pivot axis against the action ofits loading spring.

Having thus described our invention what we claim as new and desire tosecure by Letters Patent is:

A machine for making filters of the kind comprising two juxtaposedpermeable paper strips spirally wound in the form of a coil having itsconvolutions united along alternate longitudinal edges by adhesiveinitially applied to a longitudinal marginal portion of one of thestrips and to the opposite longitudinal marginal portion of the otherside of the last mentioned strip, the machine comprising in combinationa first pair of spaced guide rollers around which the adhesive-carryingstrip can pass, and which are supported on fixed axes in the region ofthe same horizontal plane, a second pair of vertically movable guiderollers around which the adhesive-carrying strip can pass after leavingone, and before passing around the second, of the first pair of guiderollers, and which are suspended respectively above and below the saidregion, a supporting roller mounted on a fixed axis at a position abovethe uppermost of the second pair of guide rollers, an elongated flexiblesuspender passing around the supporting roller and carrying the secondpair of guide rollers so that the latter can assume positions in whichthe length of the adhesive-carrying strip required to pass around bothpairs of guide rollers is sufiicient for at least one filter, andthereby enable the strip to be withdrawn from the said second roller ofthe first pair at a faster rate than that at which it is fed to theother guide roller of the first pair, a support for a coil ofadhesive-free permeable paper strip, a pair of sup- 5 4 ports for coilsof spacing tapes, a spindle which is arranged at a position between thesaid pair of supports, and also between the other support and the saidsecond roller of the first pair, to receive the adhesive-carrying stripafter it leaves the said second guide roller of the first pair, and toWithdraw the adhesive-free paper strip and spacing tapes from thecorresponding supports, and on which the paper strips and spacing tapescan be-intercoiled with the tapes between the adjacent adhesivefreelongitudinal marginal portions of the strips, and means for severing thepaper strips after predetermined lengths thereof have been intercoiledon the spindle, and preparatory to the removal of the spacing tapes fromthe intercoiled lengths of the paper strips.

References Cited in the file of this patent UNITED STATES PATENTS1,942,654 Ladd Jan. 9, 1934 1,993,728 Aivaz Mar. 12, 1935 2,064,239Aivaz Dec. 15, 1936 2,202,839 Davidson June 4, 1940 2,221,443 DavidsonNov. 12, 1940 2,242,751 McFarland May 20, 1941 2,359,475 Gauthier Oct.3, 1944 2,561,165 Arcement July 17, 1951 FOREIGN PATENTS 629,641 GermanyMay 13, 1936

